Honda Twins banner
1 - 2 of 2 Posts

·
Premium Member
Joined
·
175 Posts
Discussion Starter · #1 ·
in a CB350, there is an oil seal that goes around the cam in the points housing. the part number is 91251-km1-003. on bikebandit.com, this part is described as a "OIL SEAL (22x35x5)".

my bike was leaking oil into the points housing, so I bought a new seal from bikebandit. While installing it, I looked at the seal that was in there and it said "22 35 6" on it. it was a little bit deeper than the replacement seal, so I'm assuming that it's 1 mm deeper and that the writing on the side indicates its dimensions. I put in the new seal and since then, the bike has stopped leaking oil (at least, from that location).

my girlfriend has a very clean 1970 CB350. hers was leaking in the same location, so I assumed it was the same thing. we opened it up and found that it also had a 22x35x6 oil seal. now, her bike is basically stock while mine was built from 2 different bikes and has aftermarket pipes/air filters and who knows what else. I assumed that the person who assembled it just put in the wrong seal. I was really surprised to find that her bike had the "wrong" seal as well.

so I did some more research on this part and I've found it listed on line as 22x35x6 OR 22x35x5 - sometimes EVEN ON THE SAME PAGE! check this link:

http://www.cmsnl.com/honda-cb350-super- ... E++02.html

look at part 18 and part 19. the first has this part number with 22x35x6. immediately after that, the same part is listed as 22x35x5! this is quite frustrating.

I bought an oil seal kit from bore-tech.com but, unlike the seal I bought from bike bandit, the one included here doesn't indicate its size, so I have no idea if it's 22x35x5 or 22x35x6! I have some crappy SAE calipers so I'm going to try to measure it and see what happens.

I'm posting this here for two reasons - one to ask the community: how can the same part have two different specifications?

the other reason is to provide some warning/advice for others. in my limited experience, you want the 22x35x5 seal. the 6mm deep one seems to cause oil leaks and the 5mm one seems not to cause any leaks. I could be wrong. it could be the case that either size would work and the leaks are caused by degradation of the seal so take my advice with a grain of salt

if anyone would care to contribute to the topic, feel free!
 

·
Registered
Joined
·
59 Posts
68 69 70 had a different cam than the 71 and later. People refer to it as the big cam, it will go to 10,500 rpm's and the 71 on is a 9300 rpm.
 
1 - 2 of 2 Posts
Top